class PencilBox(object):
    a = 110

    def add(self, x, y):
        return x+y

    def draw(self):
        pass

    def circle(self):
        pass

    def draw_line(self):
        pass


class Box1(PencilBox):
    pass

    def draw(self):
        super().draw()



class Box2(PencilBox):
    pass

    def draw(self):
        pass

p = PencilBox()
p.a
p.add(400, 500)

